DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) is composed of two C4-type zinc fingers. DNA-binding domain of peroxisome proliferator-activated receptors (PPAR) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. PPAR interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of ligand-activated transcription factors. PPARs play important roles in regulating cellular differentiation, development and lipid metabolism. Activated PPAR forms a heterodimer with the retinoid X receptor (RXR) that binds to the hormone response elements, which are composed of two direct repeats of the consensus sequence 5'-AGGTCA-3' separated by one to five base pair located upstream of the peroxisome proliferator responsive genes, and interacts with co-activators. Several essential fatty acids, oxidized lipids and prostaglandin J derivatives can bind and activate PPAR. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, PPAR has a central well conserved DNA binding domain (DBD), a variable N-terminal regulatory domain, a flexible hinge and a C-terminal ligand binding domain (LBD).